diff --git a/client/client.go b/client/client.go
index 504bb1b..3ae167b 100755
--- a/client/client.go
+++ b/client/client.go
@@ -9,8 +9,8 @@ import (
 	"time"
 
 	"github.com/astaxie/beego/logs"
-        "github.com/xtaci/kcp-go"
-  
+	"github.com/xtaci/kcp-go"
+
 	"github.com/cnlh/nps/lib/common"
 	"github.com/cnlh/nps/lib/config"
 	"github.com/cnlh/nps/lib/conn"
@@ -158,7 +158,7 @@ func (s *TRPClient) newChan() {
 
 func (s *TRPClient) handleChan(src net.Conn) {
 	lk, err := conn.NewConn(src).GetLinkInfo()
-	if err != nil {
+	if err != nil || lk == nil {
 		src.Close()
 		logs.Error("get connection info from server error ", err)
 		return
@@ -245,7 +245,6 @@ func (s *TRPClient) handleUdp(serverConn net.Conn) {
 			logs.Error("unpack data error", err.Error())
 			return
 		}
-
 		raddr, err := net.ResolveUDPAddr("udp", udpData.Header.Addr.String())
 		if err != nil {
 			logs.Error("build remote addr err", err.Error())
diff --git a/lib/common/util.go b/lib/common/util.go
index 1de4455..67f58cb 100755
--- a/lib/common/util.go
+++ b/lib/common/util.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/base64"
 	"encoding/binary"
+	"errors"
 	"html/template"
 	"io"
 	"io/ioutil"
@@ -397,13 +398,61 @@ func GetExtFromPath(path string) string {
 	return string(re.Find([]byte(s[0])))
 }
 
+var externalIp string
 
 func GetExternalIp() string {
+	if externalIp != "" {
+		return externalIp
+	}
 	resp, err := http.Get("http://myexternalip.com/raw")
 	if err != nil {
 		return ""
 	}
 	defer resp.Body.Close()
 	content, _ := ioutil.ReadAll(resp.Body)
-	return string(content)
+	externalIp = string(content)
+	return externalIp
+}
+
+func GetIntranetIp() (error, string) {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return nil, ""
+	}
+	for _, address := range addrs {
+		// 检查ip地址判断是否回环地址
+		if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				return nil, ipnet.IP.To4().String()
+			}
+		}
+	}
+	return errors.New("get intranet ip error"), ""
+}
+
+func IsPublicIP(IP net.IP) bool {
+	if IP.IsLoopback() || IP.IsLinkLocalMulticast() || IP.IsLinkLocalUnicast() {
+		return false
+	}
+	if ip4 := IP.To4(); ip4 != nil {
+		switch true {
+		case ip4[0] == 10:
+			return false
+		case ip4[0] == 172 && ip4[1] >= 16 && ip4[1] <= 31:
+			return false
+		case ip4[0] == 192 && ip4[1] == 168:
+			return false
+		default:
+			return true
+		}
+	}
+	return false
+}
+
+func GetServerIpByClientIp(clientIp net.IP) string {
+	if IsPublicIP(clientIp) {
+		return GetExternalIp()
+	}
+	_, ip := GetIntranetIp()
+	return ip
 }
diff --git a/lib/conn/conn.go b/lib/conn/conn.go
index 9f0c397..8f19e6c 100755
--- a/lib/conn/conn.go
+++ b/lib/conn/conn.go
@@ -124,8 +124,8 @@ func (s *Conn) SetAlive(tp string) {
 	case *net.TCPConn:
 		conn := s.Conn.(*net.TCPConn)
 		conn.SetReadDeadline(time.Time{})
-		conn.SetKeepAlive(true)
-		conn.SetKeepAlivePeriod(time.Duration(2 * time.Second))
+		//conn.SetKeepAlive(false)
+		//conn.SetKeepAlivePeriod(time.Duration(2 * time.Second))
 	case *mux.PortConn:
 		s.Conn.(*mux.PortConn).SetReadDeadline(time.Time{})
 	}
diff --git a/server/proxy/socks5.go b/server/proxy/socks5.go
index ea78fd8..91fb451 100755
--- a/server/proxy/socks5.go
+++ b/server/proxy/socks5.go
@@ -3,7 +3,6 @@ package proxy
 import (
 	"encoding/binary"
 	"errors"
-	"fmt"
 	"io"
 	"net"
 	"strconv"
@@ -174,12 +173,7 @@ func (s *Sock5ModeServer) sendUdpReply(writeConn net.Conn, c net.Conn, rep uint8
 
 }
 
-var serveExternalIp string
-
 func (s *Sock5ModeServer) handleUDP(c net.Conn) {
-	if serveExternalIp == "" {
-		serveExternalIp = common.GetExternalIp()
-	}
 	defer c.Close()
 	addrType := make([]byte, 1)
 	c.Read(addrType)
@@ -206,7 +200,7 @@ func (s *Sock5ModeServer) handleUDP(c net.Conn) {
 	//读取端口
 	var port uint16
 	binary.Read(c, binary.BigEndian, &port)
-	fmt.Println(host, string(port))
+	logs.Warn(host, string(port))
 	replyAddr, err := net.ResolveUDPAddr("udp", s.task.ServerIp+":0")
 	if err != nil {
 		logs.Error("build local reply addr error", err)
@@ -219,9 +213,8 @@ func (s *Sock5ModeServer) handleUDP(c net.Conn) {
 		return
 	}
 	// reply the local addr
-	s.sendUdpReply(c, reply, succeeded, serveExternalIp)
+	s.sendUdpReply(c, reply, succeeded, common.GetServerIpByClientIp(c.RemoteAddr().(*net.TCPAddr).IP))
 	defer reply.Close()
-
 	// new a tunnel to client
 	link := conn.NewLink("udp", "", s.task.Client.Cnf.Crypt, s.task.Client.Cnf.Compress, c.RemoteAddr().String(), false)
 	target, err := s.bridge.SendLinkInfo(s.task.Client.Id, link, s.task)